Provided are hydrolases, including lipases, saturases, palmitases and/or stearatases, and polynucleotides encoding them, and methods of making and using these polynucleotides and polypeptides. Further provided are polypeptides, e.g., enzymes, having a hydrolase activity, e.g., lipases, saturases, palmitases and/or stearatases and methods for preparing low saturate or low trans fat oils, such as low saturate or low trans fat animal or vegetable oils, e.g., soy or canola oils.